1. Technical Field
The present invention relates to a motion analysis device and a motion analysis method.
2. Related Art
In the characteristic evaluation of a golf club, analysis of the deflection and the torsion thereof when making a swing is performed. In the past, there has been known a method of shooting the behavior of a golf club when making a swing with a camera, and then analyzing the deflection and the torsion of the golf club based on the shot image. However, since the image is analyzed in this method, there is a disadvantage that it is difficult to measure the deformation amount due to the deflection and the torsion with high accuracy, and further, it takes time from the measurement until the actual data is obtained.
On the other hand, in JP-A-2008-73210, there is proposed a method of attaching gyro sensors respectively to a head portion and a grip portion of a golf club to thereby evaluate the head speed of a swing, the carry, and so on, and it is possible to apply this method to the analysis of the deflection and the torsion of a golf club. Specifically, the deflection amount and the torsion amount of the golf club can be measured using the difference between the angular velocities detected by the two gyro sensors attached respectively to the head portion and the grip portion.
However, according to this method, since the error in the installation angle of the gyro sensor attached to the grip portion and the installation angle of the gyro sensor attached to the head portion causes the error in the detection sensitivity of the angular velocity, it is required to accurately conform the installation angles to each other. However, since the grip portion and the head portion are distant roughly 1 m from each other, it is extremely difficult to accurately conform the installation angles of the two gyro sensors to each other. If the error in the installation angle can be measured, it is possible to correct the angular velocities obtained from the gyro sensors. However, it is also extremely difficult to accurately measure the error in the installation angle. Therefore, in the case in which a high analysis accuracy is required, the method using the gyro sensors is applicable.
Such an analysis of the deformation amount due to the deflection or the torsion is performed in a variety of fields besides the golf club, and a new method realizing a high analysis accuracy has been required.